Artificial-line-selecting system.



J. F. TOOMEY & w. v. H. READ.

ARTI-FICML LINE SELECHNG SYSTEM.

APPLICATION FILED MAR. 3|. l9l].

1,277,274. Patented Aug. 27, 1918;

3 SHEETS-SHEET I.

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gu o eg 2 I I INVENTORS g N flzgomyd mal N "b "a w E 153 ATTORNEYS J. F.TOOMEY & W. V. H. READ.

ARTIFICIAL LINE SELECTING SYSTEM.

APPLICATIQN FILED MAR. 31. Ian.

1 77,274. Patented Aug. 27, 1918'.

3 SHEETSSHEET 2.

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ATTORNEYS JFiagmqg/ mead I. F. TOOMEY & W. V. H. READ.

ARTIFICIAL LINE SELECTING SYSTEM.

APPLICATION FILED MAR. 31. ml,

1,277,274. Patented Aug. 27, 1918.

a SHEETS-SHEEI 3.

JFZbomag/ 6 ii fii ead ATTORNEYS UNITED STATES PATENT OFFICE.

JOHN I. TOOMEY, OF YORK, N. Y., AND WALTER V. H. READ, F NEWARK, NEW

JERSEY, ASSIGNOBS TO AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A, COB,-

POBATION OF NEW YORK.

ABTIFICIAL-LINE-SELECTING SEYSTM.

Specification 01' Letters Patent.

Application and March 51, 1917. Serial 1%. 158,899.

To all whom it may concern:

Be it known that we, JOHN F. TooMnf and WALTER V. H. READ, residing Yorkcity and Newark, in the counties of 5 New York and Essex and States ofNew I Yorkand New Jersey, respectively, have invented certainImprovements in Artificial-'Line-Selecting Systems, of which thefollowing is a specification.

This mvention relates to telephone repeater stations and moreparticularly it relates to repeater stations of the so-called two-waytwo-repeater type wherein each transmission line section is balanced byan artificial line. Its object is to provide a system such that anyrepeater may be associated with any transmission line and further thatthe appropriate artificial line may be always associated with thetransmission line with which it is adapted to' 006 crate.

eretofore in the art it hasusually been customary tomake the'artificialline a part of the repeater organization proper. As a consequence aparticular repeater system was limited to use incoiiperation with aparticular'line or a limited number of lines for which its particularartificial line was adapted. When it was desired to o erate 0 therepeater system with a line of di erent move the artificial line andsubstitute therefor another of appropriate characteristics. When thetransmission system comprises a large number of lines it is highlydesirable to provide a more flexible system which permits of theswitching of any repeater organization into any transmission line. Inaccordance with this invention such a system has been secured byassociating the artificial line with the transmission line or lineswhich it is to balance rather than making it a part of the repeaterorganization and by providing switching means whereby the appropriateartificial line is selected when a repeater organization is connectedwith any transmission line.

The invention is best understood by referat New Referring to Fig. 1, atwo-way two-repeaterorganization is illustrated comprising two one-wayvacuum tube repeaters 1 and 1. The details of the repeaters them-,selves need not be described since they are remaining two coils 12 and13 of said transformer are serially connected by condenser 14 in outputcircuit 15 of repeater 1. Terminals 16 and 17 of coils 8 and 11respectively are connected to tip 18 and ring- 19 respectively of a twinplug 20. Terminals 21 and 22 of coils 7 and 10 respectively areconnected to tip 23 and ring 24 of twin plug 20. Opposed to plug 20 'isshown a twin jack 25,comprising a spring 26 adapted to engage tip 18, aspring 27 adapted'to engage ring 19, a spring 28 adapted to engage tip23 and a spring 29 adapted to engage ring 24', springs 26 and 27.forming the terminals of a transmission line L, while springs 28 o .and29 form the terminals of an artificial characteristics it was thennecessary to relar and equal, corresponding elements of the two halvesbeing designated by the same numerals, with and without primesrespectively.

Assuming as an illustrative example that it is desired to connect therepeater system between lines L and L for two way transmission, plug 20is plugged intojack 25 and plug 20-into jack 25, thereby connecting thetwo halves of the repeater system not only to the lines L, and L, butalso to the appropriate artificial lines N, and N,. The transmissionconnections may equally well be made by plugging plug 20 into jack 25,

and plug 20 into jack 25 since by the .ar--

rangements above described the'proper arti- Patented Aug. 27, 1918.-.

while plugs P and P ficial line is always associated with thetransmission line. It will be evident further that any two of the linesmay be connected by the repeater system.

In certain cases when a group of lines are uniform and havesubstantially the same impedance characteristics it may not be desirableto limit the use of a particular artificial line to a particular one ofsaid group since it may equally well cooperate with any other of saidgroup of lines. In such case the arrangements of this invention arepreferably those illustrated in Fig. 2. Referring to Fig. 2, therepeater organization there shown is identical with that. illustrated inFig. 1, except for the fact that cords C and U do not terminate in acommon twin plug P but in separate plugs P and P respectively, ananalogous statement applying also the cords and C Jacks 31, 32. 33, 34,35. 36, 37 and 38 form the switchboard terminals of a group of lines L LL L L L L and L respectively which have substantially the same impedancecharacteristics while jacks 39, 40, 41, 42. 43 and 44 constitute theterminals of artificial lines N N N N N and N respectively, each of saidartificial lines being adapted to cooperate with any one of the group oftransmission lines. The artificial lines may be less in number than thelines proper when traffic conditions permit. If now it is desired toconnect lines L and L for example, through repeater R for two-waytransmission, plug P is inserted in jack 31, and plug P in jack 36. PlugP may then be inserted in any one of the six artificial line jacks whileplug P may then be inserted in any other of the six artificial linejacks. An advantage of this arrangement resides in the fact that inpractice when it is extremely unlikely that all the transmission linesSllflll simultaneously be connected to repeaters it is unnecessary toprovide as'many artificial lines as thereare transmission lines.

In certain cases occurring in practice certain lines terminating at aswitchboard constitute a group having substantially the same impedancecharacteristics While other lines must each be provided with its ownappropriate artificial line. In this case cords C and C may terminate ina twin plug as shown in Flg. 1 while cords C and C may terminate inseparate plugs as shown in Fig. 2. The twin plug P is then adapted forinsert-ion, in a. twin jack may be plu ged into the separate line andartificial line Jacks of the group of lines. This compromise anrangement will be so clearly understood from the arrangements shown inFigs. 1 and 2 as not to require illustration.

The arrangement of 'acks and repeater cords at the switchboar is shownin Fig.

lines an a balancing artifiei 3 which is a drawing of the front view ofa three-repeater switchboard. Referring to Fig. 3, a group oftransmission lines ter minate at the switchboard in line jacks 41 to 55inclusive. Lines 41 to 45 inclusive are dissimilar and each is thereforeprovided with its individual artificial line, said artificial linesterminating at the switchboard in jacks 56 to 60 inclusive. Jacks 41 to45 inclusive are individually multiplied in a row of jacks 61 to (55inclusive, each of said first mentioned row of jacks being multipliedwith the jack immediately below it. The rows of jacks 61 to 65 and 56 to60 inclusive. constitute a row of twin jacks. and it will be understoodthat the artificial line of each twin jack is adapted to cooperate withthe transmission line of the same twin jack. The transmission linesterminating iujacks 46 to 55 inclusive, have substantially the sameimpedance and each of said lines is adapted to cooperate with any one ofa group of artificial lines terminating individually in a row of jacks66 to inclusive, said artificial lines being similar and equal. Threerepeaters R,. R and R terminate at the board in cords C C C and C Cordsand of repeater R, terminate in a twin plug P while cords C and G ofrepeater R terminate in a twin plug P. Cords C and C of re eater Rterminate also in a twin plug but cords C and C of repeater R terminatein separate plugs. The cords of repeater R all terminate in separateplugs.

As shown in Fig. 3 twin plug P of repeater R, is lugged into twin jack56, 61 while plug is plugged into twin jack 58, 63. Repeater R,therefore connects the lines terminating in line jacks 41 and 43. Plug Pof repeater R is logged into twin jack 6!), 65 while cords 6 and (3,. ofrepeater R, are plugged into jacks 52 and 68 respectively. epeater Rtherefore connects the lines terminating in jacks 45 and 52. Repeater Ris shown as idle but it will be understood that it could be used toconnect any two of the idle lines.

It will be further understood that the switchboard shown in Fig. 3 issimplified to clear] show the features of this invention, and t at thisinvention is not limited to the particular arrangement herein shown, butmay be embodied in various other arrangements falling within the scopeof the appended claims.

What is claimed is:

1. A repeating system comprising a plurality of transmission lines, aplurality of balancing artificial lines, a repeater and switchin one ofthe ne of similar characteristics with the repeater.

2. A repeating system comprising a plurality of transmission lines, aplurality of means to associate any a1 1 balancing artificial lines,aplurality of repeaters, and switching meansfor associating any one ofsaid repeaters-with any one of the lines and an artificial line havingcharacteristics similar to the line. I

3. A repeating system comprising a plurality of transmission lines, aplurality of artificial lines less in number than the transmissionlines, each of said artificial lines having characteristics similar toone ormore transmission lines, a repeater and switching means forassociating said re eater with a transmission line, and an arti cialline having similar characteristics.

4. A repeatingsystem comprising a plurality of transmission lines, aplurality of artificial lines less in number than the trans missionlines, each of said, artificial lines having characteristics similar toone or more transmission lines, a lurality of repeaters, and switchingmeans or associating any repeater lines and an artificial linecharacteristics.

5. A repeater system comprising a pluhaving similar with any one of saidtransmission rality of transmission lines, a plurality of balancingartificial lines, a repeater and switching means for simultaneouslyassociating a transmission line and an artificial line of similarcharacteristics with said repeater. a

- 6. In a repeater system, a transmission line and a balancingartificial line terminating in a twin jack, and a repeater having itsline connection and balancing connection terminating in a twin plug,whereby upon inserting the twin plug in the twin jack, the transmissionline and artificial line will be simultaneously connected to therepeater circuit. I

In testimony whereof we have signed our names to this specification inthe presence 7 of two subscribing witnesses, this 27th day of March,1917.

JOHN F. TOOMEY. WALTER V. H. READ.

Witnesses SAMUEL RASUNSAN, Amman KAUF'MANN.

